Conditional return using Cursors

I am new to DB2, and writing stored procedures, so I'm looking for help. I'm sure this has been asked and answered many times, and I've probably seen the answer already, but being so new to this stuff, didn't realize I was looking at my answer. I'm writing a stored procedure, and we use Cursors at my company, so the stored procedure must be written using Cursors. This is basically what I would like the stored procedure to do:

IN var1 NUMERIC(9),
IN var2 NUMERIC(9),
IN var3 CHARACTER(2)

DECLARE RESULTSET1 CURSOR WITH RETURN FOR
WITH subquery1 as (
SELECT * FROM table1
WHERE field1 = var1)

SELECT * FROM subquery1
WHERE field2 = var2;

this is where I need help
If RESULTSET1 returned results great OPEN RESULTSET1; END;
BUT, if RESULTSET1 is empty/null/returned no results run this query

SELECT * FROM subquery1
WHERE field2 = var3;



Any help would be greatly appreciated.